Extracting and transforming data from complex domains is usually an expensive exercise that consumes a lot of system resources (i.e. CPU cycles, network bandwidth, and disk space). Hence, the concept of data warehouses was developed so data from different domains would be extracted and transformed once, and new data could be appended to it. Hence, the separate temporary database system would become a permanent system where the new extracts and transformations from the order and truck domains are being loaded into.